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Ductless heating/air conditioning vs. Duct heating/air conditioning

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Newbie
May 29, 2007
10 posts

Ductless heating/air conditioning vs. Duct heating/air conditioning

Hello everyone:
We just purchased our first home and the house does have a hot water tank, however, is only equipped with baseboard electrical heating throughout the house. We wanted to upgrade our heating to either going with the expensive(installing duct work throughout the house) or considering going with the cheaper(installing the ductless system for both airconditioning and heating the house). Wanted to get any views from professionals or other homeowners that have the same conumdrum. In the long run, what option would be the best in your opinions. Please let me know your thoughts.

Thanks in advance
Ron
Ron :)
20 replies
Sr. Member
Dec 27, 2007
644 posts
4 upvotes
We have an older home that has radiant heating and ductless AC. I rather like the heating (less noise and dust).

In fact, for space heating, I've picked up an oil-filled rad.

The AC is adequate, but not ideal. As expected, there are parts of the house that are very cold, and others that are warm. I would imagine that installing a heat exchanger in a fixed location (two in one unit) would have the same temp distribution issues.

Not much can be done except to add a unit or two to supplement the system. (Opening/closing doors can help to balance the temps, but it's not terribly convenient.)
Member
Nov 13, 2007
223 posts
34 upvotes
Toronto
As bythehour has mentioned, the dustless A/C is good to a point. If you have an open concept house then the air will flow freely to all corners and cool nicely. Our house has this type of layout and the main floor is cooled perfectly. The upstairs in our house is typical to most houses and the bedrooms are all sectioned off. the air has no way of getting to these rooms...and we have a second head at the top of the stairs that delivers the cold air. I love my radiant heating but if you really value the A/C and the electric baseboards are not doing what you want, then you may want to convert over to forced air. It will be a mess while installing but I think overall it is the best solution for heating and a/c. Plus you can add a humidifier and air quality products as you see fit.
Deal Addict
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Jan 28, 2008
1177 posts
29 upvotes
Sarnia
If you already have electric baseboard heating then having a ductless a/c that can also heat isn't going to save you any money in the heat mode.. You'll be wasting money when all you need is just a ductless a/c without the heating capability for summertime cooling.
In the long run converting your house to forced air gas heating and airconditioning is the better choice.
Even a fool, when he holdeth his peace, is counted wise: and he that shutteth his lips is esteemed a man of understanding. Proverbs 17;28
Deal Addict
Jan 23, 2002
4014 posts
31 upvotes
in my limited research on ductless AC with heatpumps, I've read that the heatpumps do not perform well in colder climates like ours - good in fall and spring, but not designed for our winters. I think the choice of if you should go with forced air with ducts depends on the square-footage of your home and the length of time you expect to live there. With a smaller sq-f you may find the electric to be adequate. Consider how long you expect to live there are you want some chance at a return on the investment.
Sr. Member
User avatar
Apr 21, 2004
816 posts
43 upvotes
Pickering
We bought an older bungalow with the same issue of electric baseboard heaters throughout the house. We have no basement, only a 3ft crawl space under 85% of the house, and another room situated in what used to be a garage (so sitting on a slab).

Having lived with forced air all my life, I found the the baseboard heating to be quite uncomfortable. Hot and cold spots scattered throughout the house during winter, coupled with insufficient cooling in summer from the window and portable units.

The first few winter months, I had all the heaters going, and our electricity bill gave me a bit of sticker shock. In an attempt to lower the monthly bills, we decided to allow some rooms to be colder than others, but as our house is only 1600sq ft, I found that I did use the other rooms quite often and I was dreading having to fetch things from those rooms. Even the rooms that were heated, I found we did have quite a few hot and cold spots.

We decided our house would be a long term home, so we did go through with retrofitting a forced air system. It cost a lot for getting plans drawn up, getting permits done and made a mess of the house during installation, but the end result has been the most comfortable winter so far and manageable monthly bills.

Because of the design of the house, we had to install the furnace in the attic and all the duct work is in the attic with R12 insulated ducts. We had 3 quotes, and all of them were in the $15k-$18k range which seems like a lot (especially for a mid-efficiency), but there was quite a lot of labour.

A new gas line had to be run from the street (Enbridge), and a new meter installed. From there, the contractors we hired ran gas lines for a new tankless, the furnace, the BBQ at the back, new gas range and gas dryer.
Plans were drawn up for the heat loss calculations, so the HVAC engineer specified everything such as duct sizing and locations of all items. The contractors followed those plans to install the ducts in the attic and wrapped the main channels with R12, and used R12 insulated flexible ducts for the feeder lines.

We went with variable speed mid efficiency because one of the problems with the high is that it produces a lot of water and the risk of freezing the drain lines is greater. We were offered ways around it (such as heated drains), but we decided to go with something simpler and still reasonably efficient.

It is a night and day difference from when we first got the house to now. You can calculate what your break even point is with actual costs, but the comfort of you own home is something that really is up to you to decide its worth.
Member
May 17, 2006
453 posts
24 upvotes
I was/am in the same boat as you. I just purchased a 4 year-old house in New Brunswick, with electric heat and ductless mini-split (heat pump and A/C). The house has natural gas and an HRV. So, the builder had the opportunity to have forced air installed, what with the NG and ducts run for the HRV. Why on earth the original purchaser didn't have this done is beyond me. Actually, funny enough, MANY people here in Moncton are afraid of NG, even today. Think "BOOOOM".

Anyway, I too investigated having ducts installed for central A/C and heat, and all my research pointed to around $15k. Didn't have any quotes done as I wasn't prepared to spend this amount on essentially a brand new house. I'm willing to see how cold the house gets by regulating temps in different rooms with the electric heat, and replaced many of the simple dial thermostats with programmable ones. I'm also waiting to see what my first electricity bill is going to be.

However, my thoughts on the heat pump/mini split system is different than above, based on my research. Electric heat is, by design, 100% efficient. All energy is converted into heat. Through searching, and product literature, the heat pump CAN be up to 300% more efficient: that is, for every 1 unit of energy consumed, 3 units of heat is generated. Now, this depends on the outside temperature, but this morning was -15 in Moncton, and the heat pump in the bedroom was pumping out nice hot air when I woke up (it's on a timer). My searches have revealed that pretty much any temp below this morning, the efficiency drops off, so I'll see just how cold it can get before I get no heat from the heat pump. Haven't had the chance to use the a/c function, but I'm sure my experience will be the same as others. At least there's one unit on the main floor, and one in the master!

I congratulate Regin8r for putting up the $$ and with the mess that I'm sure ensued during the work. I would really love to get forced air installed, but can't justify the up front cost.
Deal Addict
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Jan 28, 2008
1177 posts
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Sarnia
Down to a certain temperature a heat pump can draw heat from outside and pump it into your house negating the use of electrical resistance heating other than for the fan to blow that heat around.. However most if not all heat pumps rely on a built in electrical resistance heater to compensate and boost the heat output into the room when the outside temperature is too low to adequately do it's job. So while at -15 you think your heat pump is functioning solely without using any electricity you could very well be mistaken and it's acutally running heating coils
Even a fool, when he holdeth his peace, is counted wise: and he that shutteth his lips is esteemed a man of understanding. Proverbs 17;28
Member
May 17, 2006
453 posts
24 upvotes
pkguy wrote:
Nov 25th, 2008 12:24 pm
Down to a certain temperature a heat pump can draw heat from outside and pump it into your house negating the use of electrical resistance heating other than for the fan to blow that heat around.. However most if not all heat pumps rely on a built in electrical resistance heater to compensate and boost the heat output into the room when the outside temperature is too low to adequately do it's job. So while at -15 you think your heat pump is functioning solely without using any electricity you could very well be mistaken and it's acutally running heating coils
Hmmm...didn't know this. Manual doesn't say anything about this "feature". It DOES state that at lower temperatures, the heat pump may not provide adequate heat and additional heat sources may be required.
Member
User avatar
Sep 20, 2005
403 posts
12 upvotes
pkguy wrote:
Nov 25th, 2008 12:24 pm
Down to a certain temperature a heat pump can draw heat from outside and pump it into your house negating the use of electrical resistance heating other than for the fan to blow that heat around.. However most if not all heat pumps rely on a built in electrical resistance heater to compensate and boost the heat output into the room when the outside temperature is too low to adequately do it's job. So while at -15 you think your heat pump is functioning solely without using any electricity you could very well be mistaken and it's acutally running heating coils
I think that depends on the unit you buy. I purchased a fujitsu (halcyon) 15RLQ heat pump last spring. My house is 1250 sq feet on the main floor and is a split level design. This was the most efficient unit you could buy in it's size at 20 seer cooling and 10 HSPF heating. I do not believe there is a heating coil in the unit, however, there is a sensor that will turn off the unit at -15 celsius. So far, I love this thing as it has saved a bundle of dollars thus far. I average about 10 to 15 KWH less per day than last year and we have had some cold nights. Something to note though as you must leave your doors open to allow proper air circulation. If you go ductless, I would reccomend going with Fujitsu or Mr. Slim by Mitsubishi. They are more money, but, in the end, you get what you pay for and it is well worth the investment. Stay away from the E-bay stuff as not only are they in-efficient, but you may also find it hard to find an HVAC contractor to install it.
Sr. Member
Dec 5, 2007
543 posts
1 upvote
NB
I'm not a fan of bumping old threads but in case someone finds this one at a later date looking at options for ducted versus ductless A/C or heat pumps, I'll add my $0.02 to the discussion.

There are a few items to consider:

1) Is your house already constructed?

If the answer is yes, then you are almost certainly better off going with a ductless system. It will be cheaper and more than likely more energy efficient than a large heat pump. Mine was already constructed and the ductwork install alone would have allowed me to install 2.5 ductless systems so that was a no brainer.

If your house is being constructed, then you have options. Ductwork is still a significant expense for materials, but some may prefer the hidden system to something hanging from a wall (I personally think the ductless systems are as attractive as any appliance but some may differ). The labor costs to install the ductwork will be greatly reduced before drywall has been installed in the house so it is something to consider if you prefer the non-visible look and find the costs acceptable.

2) Is the heat pump rated for your climate zone?

Not all heat pumps are created equally. The traditional air to air heat pumps used in southern climates have been optomized for A/C and don't work well below freezing because the efficiency drops significantly. Some heat pumps like the Fujitsu Halcyon and the Mitsubishi Mr Slim ductless systems are rated for low temps seen in northern climates (the system's spec sheets from the manufacturer should state the lowest operating temp). My Fujitsu 15RLQ ductless heat pump will put out great heat down to -20C so do your homework when buying your model.

Do keep in mind that living in Canada you will need to have backup heat (electric baseboard, oil, propane, NG, etc) for use during the few weeks of extreme cold weather in winter (ie when temps go below the operating range of the system) if you do go with an air to air heat pump.

3) What is the system's efficiency (SEER, EER, HSPF rating)?

These terms are confusing to a buyer, but know that the higher the rating, the more efficient the system is and the more money it should save you in the end on energy costs. The SEER (Seasonal Energy Efficiency Rating) and EER (Energy Efficiency Ratio) ratings are used to denote A/C system performance while the HSPF (Heating Seasonal Performance Factor) rating is used for heating performance. You also want to look for systems at a minimum that are Energy Star rated which will mean they have at least a SEER (Seasonal Energy Efficiency Rating) of 15 or more (units BTUs/W-hr of cooling). For reference most geothermal units have a SEER rating of around 18-25 and can function regardless of outdoor temps but the cost will be around 3-6 times that of any ducted or ductless air to air heat pump system. The HSPF tells you how efficienctly a heat pump will put out heat (units BTUs/W-hr of heat). Again geothermal is the gold standard right now at an HSPF of 10-13, but some ductless systems on the market will have an HSPF or 12 or more.

So what does this all mean? First you should know that for each watt of electric power, you can get approximately 3.4 BTUs (british thermal units) of heating. So for example if you have an HSPF of 12, that would mean that the unit has an efficiency of 12 / 3.4 = 3.5 or 350% efficient. Translated into plain english it means that for each kilowatt of power you pay for, you get 3.5 kilowatts of heating......2.5 of which were free! This free heat is transferred from the outdoors through the refrigerant circulating in the system and heat can be captured even at very cold outdoor temps (see #2 above). By comparison, baseboard heating is only 100% efficient which means you pay for one kilowatt of power and you get one kilowatt of heating. You can see how you'd see a return on your investment very quickly with higher efficiency heat pumps and that rate of return increases as electric rates in your province climb.

4) Ductless vs Ducted

One thing to keep in mind is that the efficiencies of the heat pump are usually done in perfect conditions and assume things like perfect ductwork. Any pumping losses (right angles, long runs, restrictions, imperfect sealing, etc) or insulating losses (ducts exposed to uninsulated spaces, imperfect insulation, etc) will detract from the efficency of the system so you should assume some derating of your ducted system (SEER, EER and HSPF) unless you can ensure your losses are minimal (hard to do accurately until after it is all installed). Ductless systems will perform exactly as they are rated since there is no ductwork for pumping/insulating losses.

5) Comfort

One might assume ducted systems tend to be the most comfortable and in an ideal situation you'd likely be right. Unfortunately heating and cooling capacities are not often balanced perfectly so it is important for any system to be able to balance the demands on the system using the least amount of energy possible. Many heat pumps still balance temperature by turning full on / off within a range of temps set by your thermostat.....this is very inefficient and uncomfortable! You want to make sure you look for a heat pump system that uses inverter technology which has the ability to throttle back the compressor's performance in very fine increments (as opposed to simply on/off) to match the indoor needs of the house. This technology will make a significant difference in how efficient the unit is and how closely the system is able to keep the temp in your house exactly where you set it (significantly improving your comfort at the same time). Again the Fuijitsu Halcyon ductless system does have this as do others so do your homework beforehand.

Hopefully this gives people a little more to make an informed decision and get the system that will work best for them.
Newbie
User avatar
Sep 1, 2007
27 posts
synaptech wrote:
Nov 25th, 2008 1:11 am
in my limited research on ductless AC with heatpumps, I've read that the heatpumps do not perform well in colder climates like ours - good in fall and spring, but not designed for our winters. I think the choice of if you should go with forced air with ducts depends on the square-footage of your home and the length of time you expect to live there. With a smaller sq-f you may find the electric to be adequate. Consider how long you expect to live there are you want some chance at a return on the investment.

Hi - I am looking into this now and Mitsubishi (at least) has introduced models that perform well down to -25 degrees Celsius. They seem to be about $300 more.
Newbie
Jan 30, 2006
63 posts
Toronto
Trizi wrote:
Apr 27th, 2011 10:33 am
Hi - I am looking into this now and Mitsubishi (at least) has introduced models that perform well down to -25 degrees Celsius. They seem to be about $300 more.


do you have model #'s and prices? name of installer?
pm me if you don't feel like giving out the details on here.

thanks
Jr. Member
Dec 3, 2006
163 posts
2 upvotes
0
I purchased an 18 year old bungalow with finished basement. Insulated the attic to R-50. I also had only baseboard heating.

I bought two Fujitsu ductless units:

1) 15 RLQ: installed in the living room on main floor
2) 24 RLQ (?): this one is a unit that has one outdoor unit and splits into two indoor units...one going to the basement and the other to the main bedroom

My experiences is that i save a ton in electricity. The previous owners had equal billing at $340 and mine went down to $230. Mind you, they were 3 people and i am by myself. I use the unit in the basement and the main living rooms all day and evening. I shut them off by timer around 1:00 am until 6:00 am. I use the one in the bedroom if it happens to be a bit cold during the night.

For AC, i use the one in the main living room to keep the house cool upstairs. Once in a while i'll use the one in the basement.

My experience is that they are fine for AC. The house isn't humid or hot or uncomfortable at all during the summer. If you're looking for perfect distribution, go with a ducted system, but i am really happy with how it performs.

For the heating, it does shutoff (or defrost) for about 10 to 15 minutes once in a while. I find it happens more when we have precipitation rather than because of the cold. It doesn't heat my basement enough for a few weeks to a month in the coldest time of winter, so i just turn on the baseboard for maybe 30 minutes and it's fine. Please note, that i am always in the basement to watch TV, so it might not be a problem for everyone.

If i had to do it over, i would probably keep the unit in the living room, but only have a 12RLS unit for the basement instead of having the unit split into two (bedroom and basement). That way, it would heat my basement on its own.

One thing i recommend is make sure you place the outdoor units where they would be best hidden from precipitation.

Good luck!
Newbie
User avatar
Sep 1, 2007
27 posts
cdr108 wrote:
May 4th, 2011 2:40 am
do you have model #'s and prices? name of installer?
pm me if you don't feel like giving out the details on here.

thanks

I called Mistubishi Electric directly and they put me in touch with a local distributor (Mits in Mississauga) who gave me names of installers.

There is a Mitsubishi MSZ-FE12NA (quoted at $2,700) and FE09NA, both of which operate even if the outdoor temperature hits - 25 degrees Celsius.
Another model MSZ-GE12NA works down to -20 degrees Celsius.

One that is being discontinued is the MSZ-A12NA (quoted at $2,250) which operates as low as -10 degrees Celsius.

On days colder than that, I have base board heaters already in the rooms, so I would have to switch to those.

I got some weather data from environment Canada for the past 5 years, (Jan, Feb, Mar) so I can count how many days the temp goes below -10. Also I am very near Lake Ontario, so I have a question in to them asking if they can quantify how many degrees proximity to the lake would moderate the temperatures (2 degrees? 10 degrees? so I can make adjustments to the data for my location)

I haven't chosen one yet, if it's just a couple of degrees difference then I have to go with the FE model, but if there's a significant difference I may
be able to use the discontinued model.
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